Enumerations

Another top level type that eTrice introduces is the Enumeration. Enumerations are well known from many programming languages. They basically are a lists of literals, each of which is a pair consisting of a name and an integer constant.

The assignment of integer constants is optional in eTrice. If no value is specified then the value is that of the predecessor plus one or 0 if there is no predecessor.

The default type of the enumeration is an int and depends on the target platform. But it is also possible to explicitly associate a PrimitiveType (of integer type of course) with the enumeration.

RoomModel EnumExample {

PrimitiveType int16: ptInteger -> short(Short) default "0"
PrimitiveType char: ptCharacter -> char(Char) default ""

Enumeration FirstEnum {
   zero,// 0
   one,// 1
   two,// 2
   three// 3
}

Enumeration SecondEnum {
   one = 1,// 1
   two,// 2
   three// 3
}

Enumeration ThirdEnum {
   one = 1,// 1
   two,// 2
   five = 5// 5
}

Enumeration FourthEnum {
   one = 1,// 1
   three = 3,// 3
   sixtyfive = 0x41// 0x41 or 65
}

Enumeration FifthEnum of int16 {
   f1 = 0x1,// 0x1 or 1
   f2 = 0x2,// 0x2 or 2
   f3 = 0x4,// 0x4 or 4
   f4 = 0x8// 0x8 or 8
}

Enumeration WrongType of char /* <- ERROR: no integer primitive type */ {
   c
}

Enumeration EmptyEnum {
   // ERROR: no literals defined
}

}

Listing 5.2: ROOM example code

5.5 Enumerations